增殖放流影响下东海北部海域三疣梭子蟹(Portunus trituberculatus)最大可持续产量评估

ASSESSMENT OF THE MAXIMUM SUSTAINABLE YIELD OF PORTUNUS TRITUBERCULATUS IN THE NORTHERN AREAS OF THE EAST CHINA SEA UNDER THE IMPACT OF STOCK ENHANCEMENT

当渔业资源出现衰退时,加强资源增殖放流以养护渔业资源、提高渔业产量对于渔业资源可持续利用具有重要意义;与此同时,增殖放流的实施会对基于资源开发与管理的评估的结果产生影响。基于2001~2015年间东海北部海域三疣梭子蟹(Portunus trituberculatus)渔业数据,采用增殖剩余产量模型,对东海北部海域三疣梭子蟹的最大可持续产量(MSY)及取得MSY时所需捕捞努力量(EMSY)和原存生物量(B_(MSY))进行了评估,并与传统Schaefer模型评估结果进行了比较。结果表明,当年增殖放流量约在3×10^(6)~95×10^(6)尾之间时,三疣梭子蟹年产量逐渐增加,MSY在14.2×10^(4)t和14.6×10^(4)t之间,EMSY基本在15×10^(4)吨位左右。增殖放流量增加,其对应的MSY也越高,能承受的EMSY也越高(从15×10^(4)~15.4×10^(4)吨位之间),相反B_(MSY)则减小(从188.4×10^(4)t降至186.6×10^(4)t)。与传统的Schaefer模型评估结果相比,增殖剩余产量模型由于考虑了增殖放流生物量的因素,得到了MSY和EMSY有所增加,而B_(MSY)有所下降的结论。研究结果有望为该研究海域三疣梭子蟹可持续地捕捞、放流与管理提供科学依据。

To prevent fishery resources from declining,it is important to strengthen the stock enhancement and increase the capture for the sustainable utilization.The stock enhancement will affect the results of stock assessment of the resource development and management.The maximum sustainable yield(MSY),the fishing effort(EMSY),and biomass(B_(MSY))when obtaining the MSY were estimated using the enhancement surplus production model based on the fishery data of Portunus trituberculatus in the northern East China Sea from 2001 to 2015,and compared with the assessment results obtained from the traditional Schaefer model.Results show that the annual yield of P.trituberculatus increased gradually when the quantity of annual enhancement was between 3×10^(6)ind.and 95×10^(4)ind.,the MSY was between 14.2×10^(4)t and 14.6×10^(4)t,and the EMSY was about 15×10^(4)tonnage.The value of MSY was increased with the increase of released juveniles,and so did the corresponding EMSY from 15×10^(4)tonnage to 15.4×10^(4)tonnage,while B_(MSY)was decreased from 188.4×10^(4)t to 186.6×10^(4)t.Compared with the assessment results of the traditional Schaefer model,the enhancement surplus production model could reflect the factor of enhancement biomass,which results in the increases of MSY and EMSY,and the decrease of B_(MSY)at the same time.We hope from this study to provide a scientific basis for the capture,stock enhancement,and management of P.trituberculatus in the northern East China Sea.